During his campaign for president, Donald Trump vowed that on his first day in office he’ll ask Congress to repeal the Affordable Care Act. That puts insurance coverage for 20 million Americans, including 84,000 Mainers, into question.

Trump also promised to implement reforms that will make health care more affordable, broaden access and improve quality. But some health advocates in Maine question whether the president-elect’s proposals will actually fulfill those promises.

According to Trump’s website, no one should have to buy health insurance if they don’t want to, so he plans to eliminate the Affordable Care Act’s individual mandate. But that proposal, says Consumer for Affordable Health Care’s Emily Brostek, would only drive up premiums.

“I know Donald Trump has also said that he believes that people should not be excluded from health coverage because of pre-existing conditions, and it’s a little hard to see how those things hang together,” she says, because insurance companies need healthy members to balance the cost of sick members.

Trump also pledges to make insurance more affordable by allowing individuals to deduct premiums on their tax returns. Brostek says that would be a change from the current subsidies that are available when insurance is purchased on the online marketplace.

“Which, you know, we have concerns about, because a lot of people can’t afford to wait till the end of the year, till tax time, to get that money back, which is why the advanced tax credit through healthcare.gov has worked so well,” she says.

The uncertain future of the ACA under Trump also has Maine’s insurance co-op concerned. But Community Health Options director of communications Michael Gendreau says the co-op plans to provide health coverage for the long-term.

“We have had a few people ask us, ‘What does it mean for us?’ And despite all that we’ve heard about repealing the Affordable Care Act, or dismantling it, whatever language one wants to use, that the the legislative process ahead is not something that’s going to be like a faucet where the ACA is simply turned off one day,” he says.

With Republicans in control of both houses of Congress, Trump could have the political power necessary to make major changes to the Affordable Care Act. But independent U.S. Sen. Angus King of Maine says he hopes the direction will be reform versus repeal.

“I would hate to see us just say, ‘Well, to heck with those 20 million people who now have health insurance that didn’t have it before. They’re going to be on their own,’” he says.

Republican U.S. Sen. Susan Collins of Maine says President Barack Obama has been resistant to opening up the health care law to changes, but the Trump presidency offers a new opportunity.

“Of Republicans working with Democrats to try to fix Obamacare, and there’s a lot to fix. And there’s also provisions in the law that enjoy widespread support,” she says.

Those include allowing kids to stay on their parents’ insurance until age 26, says Collins, as well as prohibiting insurance companies from discriminating against those with pre-existing conditions.

But one other area of uncertainty under Trump is Medicaid. He wants to convert it to a block grant, which Robyn Merrill of Maine Equal Justice Partners says would reduce access to health care.

“By block granting Medicaid,” she says, “there’s a certain amount of funding that goes to states. States have more flexibility to put restrictions in place.”

It’s also unclear whether Medicaid expansion will remain an option for states.

Maine Equal Justice Partners is part of a coalition that launched a campaign this fall to put the question of expanding Medicaid on the 2018 ballot in Maine. For now, says Merrill, the option is still in play.